Question

Complete the equation of the line through (3,-1)(3,−1)left parenthesis, 3, comma, minus, 1, right parenthesis and (4,7)(4,7)left parenthesis, 4, comma, 7, right parenthesis.

Use exact numbers.

Answer 1

`(\stackrel{x_1}{3}~,~\stackrel{y_1}{-1})\qquad (\stackrel{x_2}{4}~,~\stackrel{y_2}{7}) ~\hfill \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{7}-\stackrel{y1}{(-1)}}}{\underset{run} {\underset{x_2}{4}-\underset{x_1}{3}}}\implies \cfrac{7+1}{1}\implies 8 \\\\\\ \begin{array}ll \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{(-1)}=\stackrel{m}{8}(x-\stackrel{x_1}{3}) \\\\\\ y+1=8x-24\implies y=8x-25`